As the marine ecosystem is highly interconnected through predator-prey relations, the direct impacts of ocean climate change have 'knock-on' effects through the food chain. For example, recent warmer conditions and associated shifts in plankton abundance and geographical distribution have led to reduced availability of prey fish for some seabirds, which has been strongly linked to recent poor breeding success and reduced survival rates.

A 1,000-km northward shift of warmer-water plankton, with a similar retreat of colder-water plankton, has been observed in the north-east Atlantic over the past 50 years, as the seas around the UK have become warmer.

In the North Sea, the population of the previously dominant and important cold-water zooplankton species Calanus finmarchicus has declined in biomass by 70% since the 1960s.

The seasonal timing of plankton production has altered in response to recent climate changes. Some species are occurring up to four to six weeks earlier than 20 years ago, affecting predators, including fish.

Continued increase in sea temperature, due to climate change and associated changes such as ocean acidification, are likely to exert major influences on plankton abundance and geographical distributions, with implications for primary production and climate control.

Abundances of warm-water fish species (e.g. red mullet, John Dory, triggerfish) have increased in UK waters during recent decades, while many cold-water species have experienced declines.

There has been a notable influx of snake pipefish to UK waters since 2004, and research is under way to explain this.

Poor 'recruitment' of juvenile cod may be associated with a climate-related shift in the composition of zooplankton, but also by a reduction of the adult, parental population by fishing.

In some parts of the southern North Sea, cold-water species, such as cod and eelpout, have been shown to experience metabolic stress during warm years, as evidenced by slower growth rates and difficulties in supplying oxygen to body tissues.

Climate change will have far-reaching impacts on the dynamics of fish populations; however, current knowledge of underlying mechanisms is limited.

Much less is understood about the possible future impacts of climate change on non-commercial fish species, compared to those targeted by fisheries.

Range shifts have been observed in a number of cetacean species, but at present it is not possible to differentiate between short-term responses to regional resource variability and longer-term ones driven by climate change.

Poor breeding success and reduced survival of black-legged kittiwakes in recent years have been strongly linked to warmer winters and changes to their fish prey populations (e.g. smaller, less-nutritious sand eels, increased snake pipefish abundance). Other seabird species may have been similarly affected.

Some species will have difficulties in adapting to changing prey availability.

Long-term climate change will result in a northwards shift in the range of some species and consequently a decline in UK population size.

Anticipated sea-level rise and a greater number of more severe storms may reduce available breeding habitat for shoreline-nesting species (e.g. terns) and wash away nests.

Some warm-water invertebrates and algae show continued increases in abundance and have extended their ranges around northern Scotland and eastwards along the English Channel over the last 20 years.

The warm-water seaweed Bifurcaria bifurcata has established a new range boundary at Portland Headland in the last five years, 150 km east of previous records.

Cold-water species (e.g. the acorn barnacle and dabberlocks alga) have continued to decrease in abundance throughout the period 2001-2007.

Projected changes in sea level and storms may have important indirect impacts, as more sea defences are required. These act as artificial rocky shores allowing intertidal species to unnaturally extend their range.

Continued extension and retraction of ranges within the UK, with rising temperatures of southern and northern species respectively.

Some new species will become established, whilst others will disappear from our shores.

Coastal habitats are being lost around the UK. In England, it is estimated that at least 40-100 hectares of saltmarsh is being lost every year; projects are under way to estimate rates of loss in other regions.